Grin, Crazy Horse and E Street Band veteran Nils Lofgren has set August 21 as the release date for a 16 song double live album recorded with his solo group at number of stops on a recent tour.   As for the next album reuniting Bruce with the E Street Band. Lofgren characterized material the E Street Band is working on to be on a par with the best songs the band and Springsteen have ever recorded.